Business acquisition - Change in contingent consideration (Details) - USD ($) $ in Thousands	6 Months Ended	10 Months Ended
	Mar. 31, 2023	Sep. 30, 2022
Business Combination, Contingent Consideration Arrangements, Change In Amount Of Contingent Consideration, Liability [Roll Forward]
Beginning balance	$ 11,692
Ending balance	2,172	$ 11,692
Abveris
Business Combination, Contingent Consideration Arrangements, Change In Amount Of Contingent Consideration, Liability [Roll Forward]
Beginning balance	7,193	20,664
Change in fair value during the period	(5,021)	(13,471)
Ending balance	2,172	7,193
Contingent consideration | Abveris
Business Combination, Contingent Consideration Arrangements, Change In Amount Of Contingent Consideration, Liability [Roll Forward]
Beginning balance	2,100	8,500
Change in fair value during the period	(2,100)	(6,400)
Ending balance	0	2,100
Holdback | Abveris
Business Combination, Contingent Consideration Arrangements, Change In Amount Of Contingent Consideration, Liability [Roll Forward]
Beginning balance	5,093	12,164
Change in fair value during the period	(2,921)	(7,071)
Ending balance	$ 2,172	$ 5,093